SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff36ac690e5e4747e7a0a4b7d980669b7028920a6df0e08a761c886d7dd1f31a' 
  AND token = '0c5zPvL6D5j1CPFs83I0xP8uNA6s/XvACpxXZZGhehw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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