SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7e7bd8019148b6908fcc22bb249dfe40c7da7210d7cb058796d05c59fe6323a' 
  AND token = 'cHsMI77Z4W6c/nzaGcEtH85yvEXo54XgptJKkszyq7U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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