SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e845377a974edbf79348ec5ce163cda6fa4b4f1f2a825a3b90168a025360ea16' 
  AND token = 'shl62ZvL2n/88XXQ7BJooBiqLjoLvCed2hSXwH5I+sw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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