SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0eec4795728e6f21f78bf95838abdcef71058cc9b09b5cc7c54a28b6b6963ea3' 
  AND token = '6vpPqzOfA6aTnSvM+FKyiu9WUHN3uEdoDZHbc3NsBIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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