SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3c101cb67110c91b69df80a25587d1101fd727773a9d744b1a5bc1171c6ac632' 
  AND token = '5ADgvc2TrkDUo96MQtIA/Amfkea2npnpkeHwcoGSMm8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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