SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77d7b6c8104aa6d8b95f9ab3ca6312724e4a83a76e33fcef781550b9ea60a2ad' 
  AND token = 'XBR4opIZJc7TEm8Md0EFkrGQtQrugSLjJfwjdp+Up7Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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