SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd48227c91271037eebcd23506cb8201169f59ef76c7a63032f09bbeb5a54d9dd' 
  AND token = '9wNo6ChHcGWjGXLnXlbYiLIby/+N7XnsswaM90OkkTI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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