SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8fd97b9e72a142cc41eb33608d1246c4f2457f8ac3d4aa65881d6715db40abc' 
  AND token = 'eiKGxN+0D0YsFwGPNRv0Kvo33jVUpOu5n0r5OJk9PeM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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