SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5d4efc10bc0be8eaa8794619a4e41ec67989a58d475b3e0cac323383b112a194' 
  AND token = 'iHPb25RFvGt/NZCRoXnw2OYm/+SG5WhOKADPuoYzTUg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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