SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e083c777ce2cc26e09419e899540c9d6b28eb593ff7c84fc637883d16b22a174' 
  AND token = 'XqMtEG3wJw9Ov0rS/fCQMcN1JK/iwWEaHrbrGWIp2P4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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