SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a4ee1c36bf2e674e84771ad3bdba54adb3a2d4c198b22d9accb801e433a5f15' 
  AND token = 'SJcW5GMmfYG0HlUKhHjL6kIgl+yKGW6LQBng7GFRvoo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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