SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '698f0315bdbd318007d2e2e7f30ef5c26cbacbdd8fece0434d73ebe6d03554d8' 
  AND token = 'Ui57NxXiU/XRGjJEnTATKtt4Xro1h0KWPSw4xkJQzyU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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