SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7a337135fd51959f083c20db336111a21621cc1c483ae31cea74d025ab350716' 
  AND token = 'sxK+jQ/qgbIYoaZQ6ldJt7Uu8hcsQ2YdkvFAWfbA/0Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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