SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec514839564ae758eb9aaf4ca5bd2e0edc7ddc1f3b6c1a4f8822eead17ab618e' 
  AND token = 'IOvENj+33JLABT4YJDH0vErQKyquCnj+gmDmLWM6HTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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