SELECT 
  1 
FROM 
  q_lock_keys 
WHERE 
  key_id = '52796bbc179e936044a0567fc82051f0c79ac4352d737a9c3be8f3f492ae80c3' 
  AND token = 'DQiofNBrf3DBMiJ9pi6kPPKgIIOv4qzshOgawl+HsiU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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