SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f58980303b8db4d3f4515c3a4c402d4fae67cc200f63a26c16770beacf905746' 
  AND token = 'Swu6aoDLG7sUMaB018hd+Pk+sIj3ZCKTsvdXQHYsVd4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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