SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53030f7caee64926d582add01be9e5c91a4cb2acaaf7b3f8f34e5ca4e2c19e2b' 
  AND token = 'lwBM9mJjFflFQTcf5LOPboQlSUUZou+LuLKZOXbA8eU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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