SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4111407fe5afaf6a3e90d9ad9faf637b8f629aaab5d7c40324d54d315879090' 
  AND token = 'iLO71xd3/d3eEr5f8Bs5vmHP3uUEbVUO5eNOC9ujaCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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