SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06b8390c003ccebcccb18b21d8c84b87709dbcf7d7a960b6385be6333d0a1533' 
  AND token = 'CxX7KRJCXn7INPA2lWRmW4iLsnrdIsYMFPrSjULFQD8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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