SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c8f8dfeca25f015ba838ea7f87896dc88b36ff8eb53be74870dab1df09f13cf9' 
  AND token = 'vHG/NZvo6qTMg4wmW2v1zzj4sLLFlB7NNuqz13De5jE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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