SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2cd4c707598adf09690eeadd3332453ae0308f8e0b6bf9ec38540f54ebefbdec' 
  AND token = 'HtQCzKh966nhwJpdDBogsrPawpDBfPmtmzEOILPys3s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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