SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '81e665d5235c2650bc49d4a930edecd3c6e16e2c2af74ddf3dae4dcdc83dc05c' 
  AND token = 'uYW8XouAzFR3yxfB7b4QAv8DHnDeelXUCejQNy47LYA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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