SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e120645e1deed5bf6b1e6ebe31d321f92f10be5dff33ed2990ec2a94e7aaa6ae' 
  AND token = 'AdK3g2HfIii1M+QvH3OYpWIrZOdLVnggnK+x1NBbP6E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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