SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc94140072c9dd572c60778588ef17613df489e97bbf4d3be1f1b1cfd05416e2' 
  AND token = 'yMbCPl+yHzscil6ZasA9fPtIQIhJ+lL5Hxlm18FToJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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