SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46d70ee2c166e7f5d6a420a511269d2e4cb160064e04f885c5b1429ff86bcf97' 
  AND token = 'SHOAy3p4b2M1WqODYV67y50rqaSShuimgWcxG4TRljg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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