SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9550b10db90198986afef51e585f8b88a091c08743b94fd8d45da49c56735386' 
  AND token = '2OBPCAtZhMa+Lemv6fVFvgMSY+c4MX+PfjG7gpeV43c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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