SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75ae33b27d55839ad6a506cf4e8f2deca57fe9fb712fa9f3acc62e9caf18d039' 
  AND token = '/XbV19om7ok/w/ZJu9YqKWuczqB/T4SUiYIPjkg2Kac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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