SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bd57f6160dfa45aa025624305df0df1c011975f12152dded31fa4251c5a64e9' 
  AND token = 'VDEsZhqe/5vzeC/E1AhS0DWzcVi/aCBzyImSGUyj8SU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}