SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24f320e2c0ed8d0af081cb4dd9bb472dd62c6f55b85fe3d0fa91fc5c242e7670' 
  AND token = '/ru0uCFvwq50jXdZP/7X+3HCyFoJUxbq+xpZzz7Q6/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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