SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '9687ba0ad92b37a33751708353d0a23f46fa57e788bcc8d56c6b7201ddf2665a' 
  AND token = 'L5C0YTOLeBmERSfpP0UYvAkdsZ795VMZsSgMhPRy4/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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