SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '956aca0633bf7c9bb9c2efd6506bc2f41dee2f0ac5ecda71f5474cf2bec54a38' 
  AND token = 'ZKI0BhLSPGIU+88uEBVoxEJdTdJdzvFv5AYq5EozYyc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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