SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25142a299a7bfcd5fe753556fa5aed4cc083d5c90dd8549d923c835530198481' 
  AND token = 'l6Jm4vnFZ/lrqp2UWXDkMCSaznA+L3bIUTzeuzdItXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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