SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3fe7036da26c92806137cb4e92f0e3fc2df699614d342c311569ec10bf2c40e9' 
  AND token = 'j68y8sOahSufZHVIFAaSANm9z+KVvCRi3ZADeTdimEU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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