SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69b3c06fc5d4ceefebd27451d7f3b218b384212ea98f0f81b0f1d4fe023f7019' 
  AND token = 'feKGThCkAIROGCsNjGSwrH00YhqBbWZHSTWAePriDN4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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