SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff6b8e5f25b9ebb562724db2b4f9d52757de943541d87ececc7dfe251c89cad3' 
  AND token = 'EFhTG+zR0s/n1UtgXCGLD7Ol1jIh/CUi9/JZRdZXEEc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}