SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7977464fe8c36fbd1a1fcc6fd1fec11b50f4b38b2eff705e592f04d94772b6f' 
  AND token = '5bFiK9ISpJycxVlR7qQLdo8wQUoBdf+XkAGZ2cv/JjM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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