SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab6296edbfbe0c42ebd2241ad1487ca5812d3efeeb13f9cd3de800e6789357cd' 
  AND token = 'Xx7d0fwNOECJnof2In9HuA3cCecdBpKrRiqhqsR/yac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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