SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5901bbb1945a0e52ebbe30b68a29e9c373f6887186bb6dca1b57da9cc6a1b0bf' 
  AND token = 'bVFYgsU1Ln9IU6YuRCK2dhWknzqFZrM9Wtf/NzwWkXQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}