SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'faf0ff09755178ce89b58ac8cdcd3d6c63511783021e70baf01f4130abe3d7a6' 
  AND token = 'lbums/r6VVnWjKMd7qcwr26JotPB6k/uZ0X8uqB0k2U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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