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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c5d5b7521e9723c9f072798f6f6f847c57627da88ff0bc21912eef994b29aa5' 
  AND token = '3gwwL0BGPRBv4GO5zQ6M34QPqyO1CTQAbOwMk0EzT84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}