SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b7dffc33a4a6f876f89268b197c94f9adf4cbc814c1ae9d8e09e0b87c245920' 
  AND token = '0hC/MpwKkISBGpLcPNpHs7g15Q8+YiO2a4GApS36ZYs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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