SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3635ae1633c11b1bfb0fb19d6b1311422f34277bfd72f12ffce49b6ce146305d' 
  AND token = 'KVCZAPdadjPvnwHRX4QtgYnLDoAbrg7WhHIb4Lwva7I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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