Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6e5b87fca0c68a23e787d1473d772ca843174f8383d92a91c88b496505cde14' 
  AND token = '/UAh5mjxi9UXti+84xThAS/EChctpZbDDKUJJUykUAU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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