SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6479584d67af32476fca63b59622dbbe8889e3ca898cbb756de312ad5da7cbcf' 
  AND token = '5RXSmB/OZLj3uuVtLDD+rKO6qE8Z+lHArjQ0vCB0oDI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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