SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5aa66a8722aee3c65148d76d4710a647c96045869f0bd859d730de56b51e49d3' 
  AND token = '8mUradSO0yEEHuFjPH6EEzWmCxhPDfDW/Q2hBF/IrJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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