SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8b5950ff4be053a424b75137abaa9535aa38fb433f1d0d89b65dcb0554af6b8' 
  AND token = 'KY2BrqLSCrBpwBVPlh4njiHpo3G9FlJCMvZ0BbymEjc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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