SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f3bcad086adba6405e36170e9bc2caab349859c69a6ebdc88fea90cd26e8ff2' 
  AND token = 'QeGMnzTrXkafhz45Ll0U9KzgqwdmOxOwXJJFwOTLlNA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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