SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b258863c1edb0bb21da34837569bf84e97b4669644c7ae664ab014f60a06a84a' 
  AND token = 'UFnRQeI9eUEfnFK29yNhtpsmzxIHziyNocO5Xk/2kcQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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