SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08abc5dfc45f40a6c9289746da8d9ec28eb5f8e34dc56bc3d8abf5f98ffe8cbb' 
  AND token = 'L2UHX14TMeIss3NhSbDSpzG7UlI9a7rFf39ivQCMj10=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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