SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99c061b40653c2807d7d297d219a025bbbe3bfc94935255287511e12bc962eb7' 
  AND token = 'BbB3nZ7xUkQdMZTxOjXOHw6zi7Z8TRlfxWetkdpKxsc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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