SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9908825f93ebea997f3f65fc135ae350cd9ca153f5e188da018c2edfffa688b3' 
  AND token = 'BQ/XOKDgmqpATh0ErPqwKJLGxAOmGNT4v7J6UuSkprY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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