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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8144a14553bf11c08f7bf87be236bccb532bb9d44d5bd9196baa06a83172a48' 
  AND token = 'NJ9IrrcuydJ1uq80n+D0Br+WQHlVqrsRbtZBQB2G+CY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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