SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5297c04665bb7859834d63aa2ce4218692fff53c5dc0c7f04d7ba49469847e29' 
  AND token = 'w8NA6WSs/RjnWvLnzuRcrlBQW5Y/vg4evmq/ZFYFYxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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