SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa609cffc27dfe9cd6c43be3aa4242e43bc6c1292534940e7d80b261e55cd65c' 
  AND token = 'YXIM0QHGCs3qO4N7ZAOve3zNe7SVEAV8UtXiYHtxKAs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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