SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef62e933e221c31a8ce34ce2e38ecc7f80b04f89c94abe0b6515fc6199b4314e' 
  AND token = 'oJAtFFQTHRM1Qum8nUESDTyEfSpsF8+LZioscg9NGrk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}