SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd97dac269e922796f58f4093dfa75e12bcbdd832e7b2961082f250f948bf884b' 
  AND token = 'K11xLD8DtPvOARJXxlRfA9tEsWB/7lW9RddupDszus8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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