SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8df3ec07e8d1dfb6d77295da4637828243f902ff317f8c82bbcf5ef437b82a94' 
  AND token = 'TyhNvBIfAoJrMl4RKJFmLAsxQaVa/JARwGog4a60dzY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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