SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdda843f4146453f30e278894ca85a18c01b49672364439e9a3d6f2a5f9c96d4' 
  AND token = 'C9e4ZwtkiUx/Y0KbBsIq/gsqHjO4Qj+11gAMj/L6r3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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