SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8b3265d2a0115820287e7b8ea5ab8f5925e85bb47a7a093b4da3a8e2d682669' 
  AND token = 'BDJ5WEPMi/9gMbhGCMMtd93pH7aCriqunQJdwGTduvU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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