SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2b011b56d88a751fa97b3cffd9484b324637fc918bc5d1e43b95a4d053164db' 
  AND token = 'WyahIsqIptdRkEFo4KrUDrGfoTvzYp5fn+vJLsCNsSg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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