SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d7250efd57dc47fd991d96e72cb5a69db9a4ddc0c8d4f882c4fa1cf3966ba45' 
  AND token = 'CerB+b5Md7RiMxmbP4wnc/6sIgX2AmtPwq06aF9Wmfk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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