SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f98d255a3cf5d9f0f34c64684be53ccb6cec12a7c99924f0765f8131d136db32' 
  AND token = 'MCw7iBQ9yQhnaMdDT8vgB8zPV3NoikGuG9gVn/+t++Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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