SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20236481b297ff93499a5f43b1494be1ecbc6e6092ae23788e95cfd2b623c62e' 
  AND token = '9DlCaFuHg/HOcuxW9fvLRdcpqtgfGJ6wE+GGVYUiU68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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