SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85c29985fe40a4432d04a7be015c3f55a1be5027023e3cd3a34b0b8b2646708e' 
  AND token = 'RoarlLc4itt7oRaOrpZApI8S3e/Cbz1NMyUmzsnUpEk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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