SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd00e4b09685fc2510443453ee1f00eb19dfec263c25560508a8735bb19b41302' 
  AND token = 'sGd1KIWnGzAtCS+LnqYl7lW0QEPoRNiqqBW3OWODvUo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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