SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48983058c87a8cfa4cae69ac58b13ed6458c7f61f0aaefbef7b571baeeefa3fa' 
  AND token = 'LSiPflQoQeTdmLlOjg01hbeXwvSvasfj4PtgaAlF27k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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