SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1cdfb07590a48351d5f09112fd0251725948bc91087c35fc6d32a2f274a50271' 
  AND token = 'sHoZcsrRYJVIwv7iHVTHmVmgRc0mwdJCApWR1yQk2SU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00011

JSON explain

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