SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2683afafb618edb55e00fa24ad39c9384be3e3a90f96cee7e4e42b6f6e507a8' 
  AND token = 'Xz0uOdmMdGjAGGIhIbQKkywn0bpPr3Oy9RHo/vraT2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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