SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cd1fc355d93eaa9a4248fc5057982cac6764ddf2263e691e4793c74b054adc4' 
  AND token = 'lyhiYunIP+HvigMg2zYiXcIw1m0FQFVOJx9kSQsTjjo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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