SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4e73faaa9c36757003178c9be954224455fc0b2cdd70572a109f429b146f037e' 
  AND token = '4TVT6cKsHzFnCgM3IKfv5f8mF4Ng+dY4V9HyT7XGWZc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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