SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34fe8bb1899fdcf4a98d66042e632445632ed01c4943dee9ae4b9557bcb6971c' 
  AND token = 'DxzfVtL/bS0BYpfCPYL1u4+FUcjH+yLvRQV7rJ+FqH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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