SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b1253b54bc488a6b4e09a413a654f3467cff2457516c57a47c4427e9d9fc195' 
  AND token = 'LC/QV3rL+2Rs8aGyFptuIQPnhjjLhgNKL7ScHruTyfs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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