SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6955d4a300210dc5e8368c11dc0f7db96a3cdbf2de0ac6a33afdb265a438762c' 
  AND token = 'jyJVzw8bWOspSxymv23PDrxwZs2gm+IEEkwlvw6mTRA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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