SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27cf1bfb91e66347db92282a5b6245a1434e983e478558af41dd0f201ebfd014' 
  AND token = 'aekS6VrQtbSY/TQx6QDxYgiTCVI0tBOpqf8ZiheNspM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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