SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63e6b706ba269b6916c0acf09bb5f113eb9481c71b1ed73754da22a4623d1faf' 
  AND token = 'yK3PTdfP0La+PJfM37dk+EWhGfzBR+gCQJV/6eliG5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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