SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a12558352b6ce056f72133331b9172577c60d52e3df1b965230f090bf1976b5b' 
  AND token = '4SamrSE4AP+nOEr37fzXSoPtTUpt+wOpWcwho5zZzWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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