SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c64305d7badb787c61caa9ca8d5fc9f90c2479f289959ec6f12f31f8e322600e' 
  AND token = 'MHuQ0OGuSkPJcfDUrjkItzcwnTYzReI/VQ+1nGZqoFw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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