SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '825356e769316f958dd301d2b2e27cf3f8950544c4d8b0a5e27ebd23ee934126' 
  AND token = 'c4TKhdChdCXhI6cEPxRj2lmJx5UYP7YqviWi7+Uq1zk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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