SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2eb55edbd3e7f7e46c35672ab72fddee95af40e4172598892bef389c8e84b397' 
  AND token = 'Ip/8cQBynlNQo2NSau1/O/iLRfXO8CTSPpXddamKJzU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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