SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '26726cc72afcf32604332fcdcae32acd03a903142ec473d81afa23c452cecce5' 
  AND token = 'Q3eDOqDEc7uSFzRFDK2SFvYNjUVSgXcfwgEhWjvz/h0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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