SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a14cd6db72cacdae054ef1c4fc01d9f7a77cca6852b5e4411220519dbf90a711' 
  AND token = 'P6lmXTeGlwkjt0u5kP7CFRlm4aq42bcqmqsUmH/gskM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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