SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '323223f6fec8f393733a9a35e399fc9a811647f3c7eb42237cf0bbe5a4ca4c4f' 
  AND token = 'dPqDfyt49qbLqs/2xyBpogLW5PwCCAugfuNs+tLTDGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}