SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c05cf17002bb22d7b8170d10a560b883f2106cd29746d12968efbac78b08fcaf' 
  AND token = 'bhA72EGVW40YGbjkYuoRYIYO2AOcbSkb3EjdXavuwjo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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