SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a11133450eaa0088d1b73e45c3fdfea39b8f4ead482a9611eea6cf2c66a09b12' 
  AND token = 'XjRrDJRL4Ahyqi99NxByYHa33QJmaOPl7qN2rI8fc7Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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