SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40d8cded4aadfb05043394133e877843d0ca9b7b15e60b9f93ca93ccc92e4af3' 
  AND token = 'KLFFFYlsNv7wQFZVQ9PmzlG41LLVgoJTwp5A7OC1pFI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}