SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c928fe9d080bbdde65e55696b405d002e8e77c9126fd0543cf82ae95b2fdb9a' 
  AND token = 'WBbCy62XTgG3vwGXOKrz+Yl8hXvlw/ddGTR+3E4JBTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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