SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '069629022fac15bedbaf83329d81cdd60a26d744f7b45d1c9420beed207d426c' 
  AND token = 'sfYwHVjm4ss8FBza8K8Qd3MzMXwjdcoF5UfiiiuJPbs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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