SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3da9b0f93743cef1df5c44c3fc89dff35f7014dff87d35e08665fdbef7a19158' 
  AND token = 'v/nDtcfRFUX2om+A77yQZzyX0HN0yI+wumD7SSDK8ZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}