SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '948b6ab8974b4d73b57b31c1305daad4f4d78726ee11e6c7c3bb89471cb224e5' 
  AND token = 'U4hVnqqvbCdzTRgBVVEQcU3/dF+HktL37tx8xwA+IuY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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