SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccffdc9127401472a75117e050bdb5dc8a822accc54a24a9ea348925940b11fe' 
  AND token = 'FwudXDlUvrC3dIDcHlgxn6Tp0GuxkyHCHt5/C+Txfis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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