SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57f2f2310a434f2e8d6c573bfdc8233ca06a309bd5e8ba157940f4d5be7248ef' 
  AND token = 's5+WR4FD7CXApXHdYwh/JPnZORdpvK79R3XelBII9Rg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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