SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a82c8fe39b0ca0983b2bcce6647beb2ec1d963db42c5007caf68cbecaa17c92' 
  AND token = 'A4kdF4QaH88XrwXjP0VPCASCPm3PNoG4WcUxDQUFT7s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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