SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2c93dc22b21eb50b8986791cb3b974d0d00fdec570b3f1d3884d2056f647061b' 
  AND token = 'MZum0EcArqqGd8liD+YEjrJviRwttsUsVDdcawvvA9k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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