SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0c815083f53c06862dd332fe67bb7f7e9c74eac8ea06615fc1399b84eb13ec5' 
  AND token = 'thqrxPRI1h4ZNlpBw7OYHKPkq2/iC7txuRsrk8JttvU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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