SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38afcfe047e36121f94698347d78cebdf42845c17dcc4dfff0409c62147d2d1a' 
  AND token = 'YwqBAwSKwISRGhjPMoQrt3YhXTpBDDNp6Xv77VLvdwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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