SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a58ac41854db5b0481502013bc5ebbd3985c1f6cc7fa55939816f42755cae817' 
  AND token = 'bwtGYwG4rR3hJ+uC1juIT6BA8j4G+o/hOMDt59eoTZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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