SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd3fe2df52c9169926dcff1689129a3f11122610ceead05f5c967d4a54fa91eb7' 
  AND token = '4Roc08ztzVgsSNEFP1ArQybdRAhyMVGbblrS18cd804=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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