SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d273c8deedcd28e6cc19bc493f1e6ee5fa3f9df5af45ca294615300b5473d58' 
  AND token = 'RpOeGcImUrEPjCACQOinHcTC4VNu6ii4orKc0KHl5ZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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