SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '775c684671b6d940e57e9a91f88f5995fb63bc4a393e3bfb108981951d0715d3' 
  AND token = 'YjBvI/OLqi1deXp2TQXgCFcmbELxotgwHfmEnyLRLBw=' 
  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"
    }
  }
}