SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e5fced628ce63a05cd0d16d402981c8dace92ddb09a40173fcf59fdfba4f35e' 
  AND token = 'YCqUYVvJRnmQpzITRGsNeH/ffV+BPvmkzWYT6W1FEhg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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