SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77b6412cb4812c45ccc4cad3da9c151f865dd24747498d1b4b14178e410b873a' 
  AND token = 'lBlyrDiJAzBuUhr7tBUcfTcfqMKi1IZlDwTpvxJSzLM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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