SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12bded82de0e68fdc8bcea130db088806c704c6637f8e03e79ecdbcd5657a381' 
  AND token = 'drw/3ZR9EMGciykipBEsiLd26Oo6br/MDEnEzEkUb8M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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