SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc3dfb1d793a1d9f8444f1e7bb9077048fcffdccf3b5ae412c4ecb60009fcc41' 
  AND token = 'MYJy3496vPQFi03VCPc6teWYjW99Ha1ZvU5jgGS6udk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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