SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fa891e5831accf6d4def355fc59435e631d223bf1d05d667f29052f07d5f7e8' 
  AND token = 'b39y0lXHEiN7K2qKaq6qY83F3OCg5QW00DULkzniPhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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