SELECT 
  1 
FROM 
  q_lock_keys 
WHERE 
  key_id = 'c285203624299534c9d47c348f218569b65d4f3f26da703b176515d15d4aaf96' 
  AND token = 'cYvnRtdYicBeYb2I/6W7XmVYh5p5x85aPUxGGhbWW/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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