SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1d0f3cb8576153f844771a1603fe92c18372f88329bf35ab217fb8cef8f6accd' 
  AND token = 'ajo5VGAnkKc1x+m4bhGB3GEs9K643lAIU/W2rHSZYkI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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