SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33f2cd8411c828a145ea089b1f67dc6425d15bd064b53a822b80d78cdf7b4773' 
  AND token = 'afdK90ckvNc5LOQHm8Q9TOyiv7q87WVna7arr8JpzXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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