SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36dbf4e77aa6b9a3d353528ab900a4c3d6025f0db8af1984c08ddac26e8e64fa' 
  AND token = 'wsKAJrmjBazXpzKGsZx7+snvU6d04HayVkFTXB5uoPo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}