SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b5257bd1edf6e9781aac24c08fd9af83f43574f663d7531a6e95dcdc8ec687a' 
  AND token = 'LGLTuePGVbcCg352/xCYjOMhBrV8Ji3K5nJJlXG4H54=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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