SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '471314c2d6a119e233a42bce191554528a2cff3141cdacef81011c2e81ec36eb' 
  AND token = 'mLGZHYm5P2x6gHS6RJAqiBMiuEX4hq8H6a3RPZ7BfGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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