SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1913d2110aeb70460df1653c997c75ca7a3c052474f638ce3616c518002809a5' 
  AND token = 'txS9RDFauInysJtl/Of/lnJYHkCeTDN82oGwcvHFeOk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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