SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23e3c674bbc7cfd6ef6d7c8b291167c5f8c471987c419a5e62d937b18cba23e4' 
  AND token = 'lFSTEGYBg4gJmUPJCH3jywY8uoMuj+4YARDZIFvaEoM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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