SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '215208a7c5a3a511142367f17f1665287128cebc748430d44f680b29e7422b3f' 
  AND token = 'cFKT0JgZo5JfE+Ctai1I6QmMGU5pLHFTnk4S8T1036E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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