SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5568945fd3efc5b718cb687215254ff168a6e34b1a7ec660d58376b122e4b341' 
  AND token = 'OViw4mKYD/7QA2fMH9ZqQSCCyI1VMrNDsIaTRLFmOrU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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