SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ae0930963ffe528cee3aa080f965df4d09bfa900ade61e2d6fc71fbe09aad21' 
  AND token = 'Sry4aAQtmYKBoRB95zYieyvfI4OZf8C/YnomLtTGREk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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