SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c60cb15110857da55f7f95a5472f1fa3e9d51411351e42c76a3cbae9313ebf72' 
  AND token = 'A0Ip4IbG/ff3ERXKiD/ux5MZFb59fU7nxLolmJjA3kg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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