SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5bf708690829b69667e791d3450a6a662dfcdb2f6794348b1d25d60f55ee369c' 
  AND token = 'qHSxiOeXFqRPZTXzpNADCuVecnAaL59bNIAtSPmlcn0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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