SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44c07ba9fb1893d89a673d000619dc87b09a1daa5bd0e2d2c2ae093fe0897685' 
  AND token = 'lIvbWayxFBs8tn9GiQSCnrDQ9CXzNC2sccwnSzsSDxc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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