SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e57b9412cb2365a6952f611ac54bedefbc51b918987ba08acbc31bbac0c469c5' 
  AND token = 'I/1h51Lc1DOaOU1ckQCGHU8UCey3PZIGFkj61T/nUI8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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