SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa7d31f455d8a4b68bc0edb8527a8e199b7da6412b667c593c29633c67d7f958' 
  AND token = 'eHxgv885LBBojCQaSBIjeTfZILYpsZJaaYzew/FEuog=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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