SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'aa52c6c541a51dc1c8f75852648862e7d5398f06c31256ee9cc63147030e83de' 
  AND token = 'y7HuQBRJlmTgy2EHL73c6cm8nlIPtYqjth/7vZ5+kxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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