SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d72d1a756ce33ae3df5f6197043adfbc2b6ab55c1922ff0faf38bb9b295f7d4' 
  AND token = 'wpzfv/1+XrKlUmblOlRw37tSXI+zV7GR4C70BTOyrKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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