SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fe6e9c349cc8349bba896049d144b0d9782d1cd0397fe9041142ce71d5198bf' 
  AND token = '1A+/vEnoO0g2KpucvUlhTnhWDZgJD2j4wTJfKgXQYNI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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