SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fda660452100013c667ab5b096880484e63a090dcd2bf4f0e91ec335f9ac1283' 
  AND token = '0bzckilUgVTRVMsEl85yzy8OIlXvbNYmYURdbOjzPm0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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