SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e6c6505a9c4be501931540c5fad8c8be7da5976c9cd60624d758da139a22512' 
  AND token = 'YnNLjXa5linLpNT75np67OB7BFqkMbn4HMn9+CInxBU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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