SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '29ae7d152fe1857fb9be7fac011513cb08cbfde555300a716bb4285015780723' 
  AND token = 'CiyJsTgvfq+TNhaRHnTsiNm0roOXGgXtdjWuFa6Or84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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