SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'adcf680f0c6a3d21ade68061fb39e4626c2a92a78ff5cde51a8eb8c8d8d0bf19' 
  AND token = 'ImFQ0vuk61iiOPPRtFfMPrn/GQnKrJIqh82WdFK0hWY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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