SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b3d6070da809d679d56fa62aaf493b4658c5bdce39799680bcb92dbf9328d00f' 
  AND token = 'SHrAXYsxKPDA6U5F/9sfzFiam1DHJPf3f1umKr7acrY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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