SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '670ef6875f88e26c69e5fa26d85de0a194d547f0c79d36fa61fe0565ce21551c' 
  AND token = 'A2ssn0WCmuFMXprZEkwSr7CKuF/uN5JpOi/KYB5KZLA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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