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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b97f8eb059505ef049d5992dcc7b2a4b09b67d2b7e97fbfd7f9b1988d5667519' 
  AND token = '6Uwt6ZTRIWL0hIDzmEUIb+isXY/AqxA3tQ5wNZW0D1w=' 
  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"
    }
  }
}