SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e030ede03abbc6229dba36dee84cd7a5bfbfc10d2395ba7f774876cc70fee97f' 
  AND token = 'S7KeScNfB6CM3eIsYl72OTd8rhs7y+7kCuRVjRd9o04=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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