SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b39126c299648b531295540defa4e3cee023631caa4cb2710932e5a088f5d79d' 
  AND token = 'XtUY7kkGZjFFwDTRwOxyS01CnVMi3KpIix/p4L1tKfE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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