SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71acf2bc780b1c1de0b3728461799f3269fd5272cf1c8f9ef0318925ab939f39' 
  AND token = 'zPdV6InUf8nCJ6fDG25n0OSYo82ipuJhTtr6jQdFSjE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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