SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb200126a41339324fc38ae667bed44e1d0d6368b25e90c23dfefbabfe079e76' 
  AND token = 'V789vdZbvpRuaLnYn/+xBjNqGOEUMC5t8UvjB9D07eM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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