SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9affa8d6503281c8b64b1ec1731e3911c734d6aebad559439cb5a5f67518c139' 
  AND token = '/07jJpDXS/XMTCBS2zJyP+iawHXvhyHF6jIBg575Jaw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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