SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d32a26b6141c8da216358fafab68252fab6b241cfc1b1b1c9a860cddac58a79' 
  AND token = 'Mdg/td/EWrYGQgl06YyC3SAV4+4J5pzBsXeM0fqZqgg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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