SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80d64cbaaa158991f07e5b69169e791328334d8126ea723de40f9bf76e52851f' 
  AND token = 'd9E6kqBqr3ndAbGSrj3rJj+tPy2CNKXlw+Ax5ukaxC8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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