SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1afb7ea543deca633808bc704d5668136a8374f791884b63a10ca65b8b2f52d' 
  AND token = '1/H8nL+5J4O9c6QgUiKPXmNZ+yohxWHrEI5Fom+2BJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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