SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3b5b02ccabbf3cc2d955f3959f3133f8efa1e32cd6f8b981da796ebd572fee15' 
  AND token = 'J+sAHJmpPVLEVQHfn2tujegmg0NJvBASPx8ztcH8lqY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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